Alpha furyl carboxylic acid sulphonates, esters, and salts thereof



-' retested 18, 1946 um STATE s PATENT osrlce ALPHA FURYL OARBOXYLICACID SUL- PHONATES, ESTERS. AND SALTS Jack '1. Thurston, Riverside,Conn. assignor to American Cyanamid Company, New York, N. Y., acorporation of Maine No Drawing. Application October Serial No. 557,563

2 Claims. (CI. 260%45) OaM - where X is an activating group possessing apolar bond, e. g.

aliphatic. 400R, C'ONRR., -cN, -'-Noa;

and where M is a metal or hydrogen or H'NRaRaR4 where R. Ra. Re and R4are hydrogen or organic radicals. The term sulphonatef as used herein isintended to cover the hydrogen sulphonate as well as the metal, ammoniaor amine salts thereof.

The sulphonates described above may be prepared by treating a compoundof the following where X and R are the same as before, with a blsulphiteor with sulphur dioxide in a suitable medium such as water o mixtures oforganic solvents and water. Compounds of the formula may be prepared bycondensing 1 moi oi tur- 2 (where R and X are defined in the same manneras above) or vinylogs thereof.

The following examples in which the proper-- tions are in parts byweight, except as otherwise indicated, are given by way of illustrationand not in limitation and the furfural is pure.

EXAMPLE 1 Preparatlon oj ethyl 3-potossiumsulpho-3-alphajurylp ropanoateParts Ethyl furylacrylate (1 moi)" 147 Potassium metabisulphite (0.5mol) 111 Water 200 Ethylene glycol monoethyl ether 186 These substancesare mixed'together in a reaction vessel provided with an agitator and areflux condenser. The reacting mixture is refluxed for about2 hours atthe end of which time a small amount of solid material is present.

The mixtureis poure'dinto about 1 /2 times its "volume. of acetone,thereby precipitating a fine white solid. This solid material isfiltered and washed with acetone. The filtrate and washings areevaporatedvto dryness leaving an orangecolored residue which issuspended in acetone, filtered and washed with acetone. The white solidwhich remains on the filter is combined with-the white solid obtainedpreviously and .dried. Ayield of about 57% of the theoretical isobtained although analysis indicates that the product contains a. smallproportion of unreacted potassium metabisulphite.

5 Exmtn 2 Preparation of sodium 3-s0dz'ums'ulpho-3-alphalumloropanoateParts 3-alpha-furylpropenoic acid'(1.5 mols) 207 Sodium sulphite (1.5mols) 189 Water 500 rural with 1 mol oi a substance containing an activemethyl group or an active methylene mup. e. g. compounds having theformula:

These substances are placed in a reaction vessel provided with a refluxcondenser and a me-.

chanical agitator. The reacting mixture is refluxed for about 3 hours.The resulting solution is concentrated by partially evaporating thesolvent after which it is cooled, thereby precipitating a solid materialwhich is filtered. This procedure of concentrating, precipitating andfiltering the solid material is repeated several times until, finally,all of the, solvent has been evaporated. The solid material thusobtained is dried at about C. providing-a yield of about 93% 01' thetheoretical amount. The product does not melt at temperatures up to m250' o.

In order to obtain the sulphonates contemplated by my invention, it isapparent from the foregoing examples that 1 mol of furiural reacts with1 mol of a substance containing an, active methyl group or an activemethylene group and the resulting compound in turn reacts with 1 mol ofa bisulphite or sulphurous acid. It may be desirable, of course, in someinstances to employ an excess of one of the reactants in order to drivethe reaction to completion.

Other substances having an active methyl group or an active methylenegroup may be combined with iuriural and converted to the sulphonate inaccordance closure. Thus, for example, other acids and their esters maybe used, e. g. chloracetic acid, bromoacetic acid, crotonlc acid, sorbicacid, propionic acid, beta sulphopropionic acid, butyric acid, succinicacid, malonic acid, lauric acid, phenylacetic acid, oxalacetic acid,3,5-dinltro-o-toluic acid, and their esters (such as the methyl, ethyl,benzyl and phenyl esters).

Compounds having the general formula:

may be converted to the corresponding sulpho nate by treatment with abisulphite or with sulphur dioxide in a suitable medium such as water.Suitable bisulphites include sodium bisulphite, potassium bisulphite,ammonium bisulphite or any other desirable sulphite such as calciumbisulphite. In general, the alkali metal bisulphites are preferred. Thehydrogen sulphonates may be converted into the corresponding metal,ammonium or amine salts ifdesired. Examples of amines for such saltsare: methyl amine, dimethyl amine, pyridine, 'triethylamine, the mono-,diand tri-ethanolamines, etc. Another method of producing thesulphonates is by treatment of the furfurylidene compounds with ahydrogen halide followed by treatment with sodium sulphite or with thealkali metal sulphites. Thus, for example, hydrogen chloride may beadded to 3-alpha-fnrylpropenoic acid or its esters and the resultingmaterial treated with sodium sulphite. Still another type of sulphonatemay be prepared by the condensation of furfural with a halogensubstituted acid or ester such as acetic acid, followed by treatment (1)with a hydrogen halide and then with a sulphite or (2) with anequimolecular mixture of a bisulphite and a sulphite. The bisulphite orsulphite may be a salt of an alkali metal, ammonia, or any other desiredmetal or amine. Y

The sulphonates may be prepared from the furiurylidene compounds byreaction with bisulphite at temperatures ranging upwards from roomtemperature. In most instances, the reacwith the foregoing distion isadvantageously carried out at a temperature between about 70 C. andabout 130 C. If sulphur dioxide be used, the reaction is preferablycarried out under pressure, e. g. 25-400 pounds per sq. in., and/or atrelatively low. temperatures such as about 20 C, The time of reactionvaries somewhat according to the compatibility of the reactants. Thus,if a homogeneous solution of the reactants be employed, the reactionwill usually be completed in from about /2 hour to about 2 hours. On theother hand, if the solution of the reactants is not homogeneous, 6-8hours or even more may be required. Generally, water is employed as thesolvent medium for the bisuiphite and the furfurylidene compound but ifsufilcient solubility is not obtained other solvents may be used.Mixtures of water and water-miscible organic solvents are especiallysuitable since the water is a good solvent for the bisulphite, while theorganic solvent is a good solvent for the furfurylidene compound.Examples of suitable solvents are methanol, ethanol, propanol,isopropanol, tertiary butanol, dioxane, the lower alkyl mono-ethers ofethylene glycol and diethylene glycol, such as the mono-ethyl ether ofethylene glycol, the mono butyl ether of diethylene glycol, etc.Furthermore, inert ketones may be employed as solvents for the reactantsin the production of the sulphonates. In some instances it may bedesirable to employ active ketones as intermeditaes in the preparationof the sulphonates. Thus. the bisulphite may add to an active ketone andthis in turn reacts with the furfurylidene compound, the former givingup the bisulphite to the latter.

My furyl substituted sulphonic acids are espe- V cially suitable forresiniflcation with an aldehyde to produce resinous materials havingcation active-properties. They are also useful in the preparation ofemulsifiers, wetting agents, dispersing agents and as intermediates inthe synthesis of many other organic compounds.

This application is a continuation-in-part of my copending application.Serial No. 453,277, iiled Aug t 1. 1942.

Obviously, many modifications and variations in the processes andcompositions described above may be made without departing from thespirit and scope of the invention as defined in the appended claims.

I claim: 1. An ethane substituted in the 1- position with s analpha-furyl group and a sulphonate radical ing of ethanes substituted inthe 1- salts thereof.

and in the 2- position with an ester group.

2. A substance selected from the group consistposition with analpha-furyl group and a sulphonate, and in the 2- position with aradical selected from the group consisting of carboxylic acids, estersand JACK 'r. 'rrmas'ron.

